This invention pertains to seat structure, and in particular to methodology associated with anti-spring, web spanner structure for supporting an occupant-seating cushion in seat structure designed for use in the setting of high-speed vehicle, such as an aircraft, to minimize injuries in hard and/or catastrophic impact events. The method of the invention also pertains to the use of such seat structure which further includes an anti-spring, compression-load seat-base structure.
Conventional seat design, insofar as it has been aimed at minimizing injuries caused from a hard “bottoming-out” event, such as in a crash landing in an aircraft, have typically introduced structural arrangements which, unfortunately, and to some extent accidentally, tend to exacerbate the impact-injury problem. Such design often utilizes a collapsing or “stroking” behavior in an effort to minimize the total load delivered to a seat occupant. This approach, however, frequently introduces undesirable weight, complexity, and expense issues, and also additionally enhances “springiness” in a seat structure—a situation that can actually lead to an amplification of damaging accelerations applied to a seat occupant's spine. Increased springiness, counter-intuitive as this may seem, introduces an enlarged rebound counter-acceleration fractions of a second after a dangerous impact occurs, and such increased counter-acceleration significantly contributes to serious, and often fatal, injury.
The methodology of the present invention addresses this issue with an innovative seat structure which, in use, is interposed a seat occupant and a vehicle frame, such as an aircraft frame, and which possesses substantially no spring-loading and spring-back behavior. This seat structure, disclosed in the environment of an aircraft, and in a preferred and best mode embodiment and manner of use which are specifically illustrated and described herein, features a very thin, occupant-cushion-supporting spanner web formed of substantially non-stretchy and non-springy strand material, such as elongate carbon fiber, or Kevlar®, strand material, which is deployed under very modest tension between a pair of transverse, spaced, parallel, elongate and very robust cylindrical tubes. These tubes are carried on an adjustable, selectively fore and aft repositionable, slider sub-frame which, in turn, rides slideably on a pair of spaced, lateral and parallel I-beam-like rails (seat-frame substructures) which are, effectively, directly anchored to the aircraft frame. The mechanism furnished for enabling selectable slide repositioning, and positional unlocking and locking associated with this capability, do not form any part of the present invention, and are neither described nor illustrated herein.
These components of the seat frame—tubes, slider mechanism, rails and associated structures—load principally in very modest-deflection compression, rather than in bending, and consequently make an important contribution to the non-spring-back performance of the entire seat-structure. The spanner web, non-stretchable as it is, offers an extremely light weight, thin-format direct cushion support structure which also specially exhibits substantially no spring-loading, spring-back response to loading activity, such as an impact-produced sharp, high-level accelerative loading.
These and other features and advantages which are offered by the present invention will become more fully evident and appreciated as the description that now follows is read in conjunction with the accompanying drawings.